Calculate battery pack energy, runtime, and power limits. Configure series-parallel cells for realistic engineering estimates. Apply losses and discharge controls before final sizing decisions.
| Scenario | Cell V | Cell Ah | S | P | DoD % | Eff % | Load W | Usable Wh (approx) |
|---|---|---|---|---|---|---|---|---|
| Portable Tool Pack | 3.7 | 2.5 | 5 | 2 | 80 | 90 | 120 | 66.6 |
| UPS Module | 3.2 | 100 | 4 | 1 | 90 | 94 | 300 | 1082.9 |
| Solar Storage Bank | 3.2 | 280 | 16 | 1 | 85 | 95 | 2000 | 11574.4 |
Values are illustrative and may differ from manufacturer discharge curves and BMS restrictions.
Pack Voltage (V) = Cell Voltage × Series Cells
Pack Capacity (Ah) = Cell Capacity × Parallel Cells
Nominal Energy (Wh) = Pack Voltage × Pack Capacity
Usable Energy (Wh) = Nominal Energy × (DoD/100) × (Efficiency/100) × (Temperature Factor/100)
Runtime (hours) = Usable Energy ÷ Load Power
Max Continuous Current (A) = Pack Capacity × C-Rate
Max Continuous Power (W) = Pack Voltage × Max Continuous Current
This calculator uses nominal values, so peak load and voltage sag effects are not modeled.
Battery energy is commonly expressed in watt-hours, but engineering decisions depend on usable watt-hours. Nameplate values assume ideal discharge conditions and often ignore conversion losses. During planning, teams should estimate realistic delivered energy, not theoretical storage. This calculator helps translate datasheet values into practical performance outputs for sizing studies, procurement comparisons, and documentation reviews.
Series connections raise pack voltage, while parallel connections raise capacity in amp-hours. Because energy equals voltage multiplied by capacity, both variables directly influence total stored energy. Voltage also affects current demand for the same load. Higher pack voltage generally lowers current, reducing conductor losses and improving efficiency in many applications. Parallel scaling improves runtime but increases balancing and packaging requirements.
Runtime should be calculated from usable energy after derating. Depth of discharge protects cycle life and reserves capacity for safe operation. System efficiency accounts for inverter, converter, and wiring losses. Temperature factor addresses reduced capacity under cold or extreme operating environments. By combining these terms, the calculator generates a more reliable runtime estimate for field equipment, backup loads, and mobile engineering systems.
C-rate provides a quick estimate of allowable discharge current relative to battery capacity. Multiplying pack capacity by selected C-rate gives a practical current limit for early design analysis. Multiplying that current by pack voltage estimates continuous power capability. This value is useful for screening loads, checking startup requirements, and identifying whether larger parallel capacity or higher voltage architecture is needed.
Start with verified cell voltage and cell capacity from the manufacturer datasheet. Enter series and parallel counts, then apply conservative depth of discharge and efficiency assumptions. Add expected load power and a temperature factor matching the deployment environment. Review usable energy, runtime, and output limits together rather than as isolated values. Export CSV and PDF outputs to keep calculations traceable across design revisions. For higher confidence, compare calculator outputs with test data from representative duty cycles, then update assumptions before final battery selection. This disciplined process improves reliability estimates, supports stakeholder reviews, and reduces costly redesigns during commissioning and deployment.
Nominal energy is the theoretical pack rating from voltage and capacity. Usable energy applies discharge limits, efficiency losses, and temperature effects, which better reflects real operating performance.
Depth of discharge prevents overestimating runtime. Most systems avoid using 100% of stored energy to protect battery life, improve safety margins, and meet BMS operating limits.
Yes, for first-pass estimates. Enter the correct cell voltage, capacity, C-rate, and realistic derating factors. Final sizing should still be verified against the specific manufacturer datasheet.
No. It uses nominal values and simple derating assumptions. High-current behavior, transient loads, and voltage sag need detailed discharge curves or simulation for precise design validation.
Use a conservative percentage based on expected ambient conditions and datasheet guidance. Cold environments often reduce capacity, so lower factors can produce more realistic runtime estimates.
No. It is an estimate derived from pack voltage and selected C-rate. Actual continuous power depends on BMS limits, thermal performance, wiring, and the battery manufacturer’s specifications.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.